Airfoils may be used in many applications, including as blades for fans, impellers, turbines, propellers, etc. Airfoils may be manufactured from many different materials. In some cases, airfoils may be manufactured from composite materials such as polymer matrix composites (PMCs), ceramic matrix composites (CMCs), or metal matrix composites (MMCs). The airfoils may be attached to a metallic rotor at a root of the airfoil. However, in certain designs the root may comprise features undesirable for attachment to composite materials.